Taking everything off of the hull and removing the turf will be the quickest part of the process. I you're pulling the engine, pump, etc. then this job will probably take you a couple days after work if you've never done it (5-15 hours). If all you have is the pole, turf, and a few odds and ends then it shouldn't take more than a couple hours.
I have a 60 gallon air compressor with a dual action sander and I want to say it took me 10+ hours to remove the gelcoat off of everything. Repaint with automotive paint and an air sprayer took me a total of 6 days for all the coats required. However, the first day I spent maybe 2-3 hours cleaning the bottom real good and spraying. Day 2 was spent cleaning dust off the paint and adding some more paint. Day 3 was the top deck... Day 4 it rained and Day 5 I finished spraying the top deck. Day 6 you can't do much since the paint I used had a medium cure of 2 days. All in all on painting, I'd say I spent 5-10 hours with many many many more hours of waiting.
Returfing takes a lot of patience and can take quite a few days if you're doing footholds. If you're putting it back on the bottom of a stock ski, it shouldn't take more than an hour.
Putting everything back in and on the hull will take another 5-15 hours depending on experience and the number of problems you run into. Troubleshooting why things don't work the way they did when you rode last time can take all summer...
For reference...the first time I pulled my 750 apart it took many months to accomplish all of this and I typically worked on the ski 3-4+ hours a day.